1. Field of the Invention
The present invention relates to a conveying apparatus, an image forming apparatus, and a conveying control method.
2. Description of the Related Art
The so-called interleaf control system is a known technique that may be implemented in the case of performing sequential duplex printing on a plurality of sheets of recording medium in an image forming apparatus such as a copier, for example. The interleaf control system involves printing an image on a first side of a sheet of recording medium, and then alternately printing an image on a first side of a newly fed sheet of recording medium and printing an image on a second side of the sheet that already has an image printed on its first side.
In such interleaf control system, a plurality of sheets of recording medium that already have images printed on their first sides are arranged to await printing at a duplex conveying path, and the sheets of recording medium having images printed on their first sides and newly fed sheets of recording medium are alternatingly conveyed according to the print timing (see e.g. Japanese Laid-Open Patent Publication No. 2001-326785).
Note that some image forming apparatuses include a plurality of supply units that supply a recording medium to the duplex conveying path at different supply positions. In such case, the number of sheets of recording medium having images printed on their first sides that can be arranged to wait at the duplex conveying path may vary, and conveying control has to be adjusted depending on the supply unit that is supplying the recording medium.